The maximum simultaneous maintenance capability of Tianjin Electric Locomotive Co., Ltd. is 3000. Since Dec. 2011, we have passed the 2-year period maintenance capability assessment of HXD3, HXD3B and HXD3C type locomotive by the Railway Bureau, and realize batch maintenance of 2-year period maintenance of electric locomotives. And we carry out the 2nd 2-year period maintenance of HXD3 and HXD3C electric locomotive successively and realize the batch 2nd 2-year period and testing maintenance of HXD3 and HXD3C respectively.